1. Field of the Invention
This invention relates to rotor blades of high temperature turbo machinery, and more specifically to techniques for cooling such rotor blades.
2. Description of the Prior Art
Most relevant prior art is thought to be in the gas turbine engine field wherein airfoil surfaces of rotor blades are at times exposed to temperatures well in excess of two thousand five hundred degrees Fahrenheit (2500.degree. F.). Limiting the metal temperature of such blades is extremely critical in order to preserve material strength in the face of high centrifugal loads and to prevent local material deterioration.
Technical literature is replete with intricate and complex approaches to cooling rotor blades. U.S. Pat. Nos. 3,799,696 to Redman entitled "Cooled Vane or Blade for a Gas Turbine Engine";3,782,852 to Moore entitled "Gas Turbine Engine Blades"; 3,994,622 to Schultz et al entitled "Coolable Turbine Blade"; 4,022,542 to Barbeau entitled "Turbine Blade"; and 4,073,599 to Allen et al entitled "Hollow Turbine Blade Tip Closure " are representative of prior art structures.
Not withstanding disclosures of the prior art, scientists and engineers continue to search for yet improved techniques and new combinations thereof which are able to extend the effective service life of rotor blades.